I am trying to get all my data out of the database in a array or list format.
Such that I can make an for loop in the html to loop through all the names in the database.
I tried with:
all_name = name.objects.all()
the output will be shown as
<QuerySet [<allName: name1>, < allName: name2>, < allName: name3>]>
However I want to get something like:
name1;
name2; name3
What I did next is to use the .get function:
all_name = name.objects.get(id=1)
my name model:
class name(models.Model):
firstname = models.CharField(max_length=100)
def __str__(self):
return (self.firstname)
This gives me only one object with the given id.
Is there a way to get what I am looking for and display my array/list with a forloop in a html file?
You can simply try for Name model with consider allName as a attribute/column
list(Name.objects.all().values_list('allName', flat=True))
or
Name.objects.all().values_list('allName')
You can join the strings that originate from the database with:
'; '.join(map(str, name.objects.all()))
Many:
name_list = Name.objects.all().values_list('firstname', flat=True))
One:
query = name.objects.get(id=1)
name = query.firstname
Related
I have two Django models as follows:
class Event(models.Model):
name = models.CharField()
class EventPerson(models.Model):
event = models.ForeignKey('Event',on_delete='CASCADE',related_name='event_persons')
person_name = models.CharField()
If an Event exists in the database, it will have exactly two EventPerson objects that are related to it.
What I want to do is to determine if there exists an Event with a given name AND that have a given set of two people (EventPersons) in that event. Is this possible to do in a single Django query?
I know I could write python code like this to check, but I'm hoping for something more efficient:
def event_exists(eventname,person1name,person2name):
foundit=False
for evt in Event.objects.filter(name=eventname):
evtperson_names = [obj.person_name in evt.event_persons.all()]
if len(evtperson_names) == 2 and person1name in evtperson_names and person2name in evtperson_names:
foundit=True
break
return foundit
Or would it be better to refactor the models so that Event has person1name and person2name as its own fields like this:
class Event(models.Model):
name = models.CharField()
person1name = models.CharField()
person2name = models.CharField()
The problem with this is that there is no natural ordering for person1 and person2, ie if the persons are "Bob" and "Sally" then we could have person1name="Bob" and person2name="Sally" or we could have person1name="Sally" and person2name="Bob".
Suggestions?
You can query for EventPerson objects where the event name is as given instead, use the values_list to extract the person_name field, and convert the returning list of values to a set for an unordered comparison:
def event_exists(eventname, person1name, person2name):
return set(EventPerson.objects.filter(event__name=eventname).values_list(
'person_name', flat=True)) == {person1name, person2name}
I modified #blhsing answer slightly adding a filter on names.
def event_exists(eventname, person1name, person2name):
event_people = EventPerson.objects.select_related('event').filter(person_name__in=[person1name, person2name], event__name=eventname)
return set(event_people.values_list('person_name', flat=True)) person1name, person2name}
I would suggest passing EventPerson objects or theird ids to this function instead of just names, would make filtering easier (you wouldn't need a set and filter straight by ids) and more efficient (by using db indices ... or you would have to index person_name as well)
I have a django model that contains a textfield with a large amount of text. I would like to be able to query the database for this textfield and store the results in a string list. How can I do this?
something like...
views.py:
queryset = Words.object.filter(id='1')
wordArray = []
wordArray = queryset.split() # obviously this doesn't work
models.py
class Words (models.Model):
dictionary = models.TextField()
def __str__(self):
return str(self.dictionary)
try values_list()
result = Words.object.filter(id='1').values_list('dictionary',flat=True)
then to access each value and split it proceed as follows:
r_list=[]
for r in result:
r_list.append(r.split())
r_list will have all the word of all values in result.
I'm trying to make this table with a clickable field which changes the boolean for the entry to its opposite value. It works, but I want an alternative text as "False" or "True" does not look nice, and the users are mainly Norwegian.
def bool_to_norwegian(boolean):
if boolean:
return "Ja"
else:
return "Nei"
class OrderTable(tables.Table):
id = tables.LinkColumn('admin_detail', args=[A('id')])
name = tables.Column()
address = tables.Column()
order = tables.Column()
order_placed_at = tables.DateTimeColumn()
order_delivery_at = tables.DateColumn()
price = tables.Column()
comment = tables.Column()
sent = tables.LinkColumn('status_sent', args=[A('id')])
paid = tables.LinkColumn('status_paid', args=[A('id')], text=[A('paid')])
class Meta:
attrs = {'class': 'order-table'}
If you look under the "paid" entry I am testing this right now, why can't I access the data with the same accessor as I do in the args? If I change the args to args=[A('paid')] and look at the link, it does indeed have the correct data on it. The model names are the same as the ones in this table, and "paid" and "sent" are BooleanFields.
This is kind of what I ultimately want:
text=bool_to_norwegian([A('paid')])
Here is what I send to the table:
orders = Order.objects.order_by("-order_delivery_at")
orders = orders.values()
table = OrderTable(orders)
RequestConfig(request).configure(table)
The text argument expects a callable that accepts a record, and returns a text value. You are passing it a list (which it will just ignore), and your function is expecting a boolean instead of a record. There is also no need for using accessors here.
Something like this should work:
def bool_to_norwegian(record):
if record.paid:
return "Ja"
else:
return "Nei"
Then in your column:
paid = tables.LinkColumn('status_paid', text=bool_to_norwegian)
(Note, it is not clear from your question where the data is coming from - is paid a boolean? You may need to adjust this to fit).
As an aside, the way you are passing args to your columns is weird (it seems the documentation also recommends this, but I don't understand why - it's very confusing). A more standard approach would be:
id = tables.LinkColumn('admin_detail', A('id'))
or using named arguments:
id = tables.LinkColumn('admin_detail', accessor=A('id'))
def index(request):
expiring_list = probe.objects.filter("isExpired=True")
output = ', '.join([p.serial for p in expiring_list])
return HttpResponse(output)
isExpired is a Boolean function. How should I modify the filter so that the filter does not raise a ValueError?
You are making the query in a wrong format.
Your query should be of the form:
expiring_list = probe.objects.filter(isExpired = True)
This was the query you needed to make in case isExpired was your model field. But since you say its a function, assuming that function is inside the class you need to get all the objects in the following way:
expiring_list = []
objects = probe.objects.all()
for obj in objects:
if obj.isExpired() == True:
expiring_list.append(obj)
The expiring_list will now contain all the objects of the model probe where isExpired function returns True
I think isExpired is not a field in your models, as reference to your previous question Refresh a field from another table [Django]
I think exp_date is the field which you are looking for.
Try this:
import datetime
def index(request):
expiring_list = probe.objects.filter(exp_date__lt=datetime.date.today())
output = ', '.join([p.serial for p in expiring_list])
return HttpResponse(output)
I have a django model that looks something like this:
class Definition
name = models.CharField(max_length=254)
text = models.TextField()
If I do the following query:
animal = Definition.objects.get(name='Owl')
and if I have the following definitions with these names in my database:
Elephant, Owl, Zebra, Human
is there a way to do a django query(ies) that will show me the previous and the next Definitions based on the animal object based on alphabetical order of the name field in the model?
I know that there are ways of getting previous/next based on datetime fields, but I am not so sure for this case.
I don't know of any way of doing this in less than three queries.
target = 'Owl'
animal = Definition.objects.get(name=target)
previous_animal = Definition.objects.order_by('name').filter(name__lt=target)[0]
next_animal = Definition.objects.order_by('name').filter(name__gt=target)[0]
If anyone comes across this like I just did...
heres my solution... it also loops(so if on last item it shows first item as next and if on first item shows last item as previous)
def get_previous_by_title(self):
curr_title = self.get_object().title
queryset = self.my_queryset()
try:
prev = queryset.filter(title__lt=curr_title).order_by("-title")[0:1].get()
except Video.DoesNotExist:
prev = queryset.order_by("-title")[0:1].get()
return prev
def get_next_by_title(self):
curr_title = self.get_object().title
queryset = self.my_queryset()
try:
next = queryset.filter(title__gt=curr_title).order_by("title")[0:1].get()
except Video.DoesNotExist:
next = queryset.order_by("title")[0:1].get()
return next
i have custom querysets based on user level so could just set the queryset as a normal queryset like... Video.objects.all() but anyplace I repeat code more than once I make a function